In his column for the Daily Mail, Redknapp wrote: "I was playing for Spurs against Manchester United and remember looking at Cristiano Ronaldo in the tunnel and admiring his shape and physique. He looked like a footballer. At the time, plenty were dismissing him as a show pony. There was a lot of focus on his theatrical falls and tricks, without too much end product.
"After the game, I saw Sir Alex and said: 'Your No 7 isn't too bad.' He looked at me and said: 'I'm telling you, he's going to be one of the best players in the world.'
"His development of Ronaldo is an indication of his passion for the game, his knowledge and ability to spot a United player, because it's harder to play for the bigger clubs, such are the demands and expectations, the pressure to perform consistently when everyone is trying to bring you down."